NISAR SweepSAR Echo Simulation: Summary and Results

This paper presents the Radar Echo Emulator (REE), a SAR simulation tool with high fidelity and flexibility that is being used to assess and quantify the radar instrument functionality, performance, and overall impulse response for various modes of the NASA-ISRO synthetic aperture radar (NISAR) mission. NISAR is a complex multi-channel multi-polarization wide-band wide-swath high-resolution SAR instrument based on SweepSAR architecture [1]. Its radar instruments support several configurable radar modes to fulfill variety of science applications [2]. The paper provides a brief overview of the REE tool as a general SAR simulator while primarily focusing on its SweepSAR and digital beamforming (DBF) application via an example of repeat-pass four-channel L-band split-spectrum NISAR simulation over an extended Amazon rainforest-like scene [3], [4]. An example of the ionosphere effect with split-spectrum analysis and an example with radio frequency interference (RFI) contamination are also presented.